Certain codes I don't understand

[system]

The following code uses the ‘->’ several times. I have researched and cannot find its definition and usage.

Sample code

if ($x->item($i)->childNodes->item(0)->nodeValue == $q)
{
$y=($x->item($i)->parentNode);

Thank you
Mike

[richei]

They’re used in object code. I never use it personally, but i guess its pretty popular.

[m11]

It’s a DOM object (likely XML)